Due to stringent fire prevention standards for underground mining operations promulgated and enforced by the United States Department of Labor's Mine Safety and Health Administration (“MSHA”), conveyor belts for underground mining must be suitably fire-resistant. To that end, halogenated compositions, e.g., chlorinated compositions, are known to be useful in rubber compounds for providing conveyor belts with fire-resistance that meets or exceeds MSHA standards. However, while halogenated compositions may be suitable fire retardants, such compositions disadvantageously release toxic, caustic, and/or corrosive fumes and/or undesirable levels of smoke upon burning. Those by-products can be particularly dangerous and potentially lethal to miners in the relatively closed confines of an underground mine in the event that halogenated compositions burn in a mine fire. Thus, in addition to be being fire resistant it would be highly beneficial for rubber formulations used in manufacturing conveyor belts for underground mining operations to generate less harmful fumes and smoke upon burning than is produced in cases where conventional halogenated rubber compounds are utilized in making the conveyor belt. To that end, alternative rubber compounds having the physical and mechanical attributes required for use in making conveyor belts are currently in demand and would fulfill a long felt need in the industry.
Accordingly, it would be desirable to provide a suitable non-halogenated rubber compound for use in conveyor belts for underground mining, such non-halogenated rubber compound being fire-resistant in accordance with MSHA standards and producing acceptable levels of toxicity and smoke upon burning.